There are at least 8 artists called "X".
These are photos from concerts where X played, so they may be of other bands that played the concert as well.
X Nov 3, 1983 Washington, D.C., United States Uploaded by Jeffrey Lee
Oingo Boingo / X Aug 20, 1983 Costa Mesa, California, United States Uploaded by Milocampo
X / D.O.A. / The Untouchables / The Flesheaters / The Hunting Game May 7, 1983 Sacramento, California, United States Uploaded by Sacramento Shows
X Oct 13, 1982 Sacramento, California, United States Uploaded by Sacramento Shows
X / The Fleshtones Jul 9, 1982 Washington, D.C., United States Uploaded by Jeffrey Lee
Iggy Pop / X / Boomtown Rats Nov 20, 1981 Los Angeles, California, United States Uploaded by Zimtrim
X / The Brat / No Alternative / Wilma Aug 8, 1981 San Francisco, California, United States Uploaded by Yvette Kay
Urgh! A Music War / Dead Kennedys / Bad Brains / X / Cramps / Chelsea Aug 15, 1980 Santa Monica CA Uploaded by Stephenhuerta
Circle Jerks / X / Alley Cats / Urinals / Gun Club May 9, 1980 Redondo Beach, California, United States Uploaded by Evan Rude
The Boomtown Rats / X Apr 20, 1980 Los Angeles, California, United States Uploaded by Wicked Goddess
Circle Jerks / X Apr 4, 1980 San Diego, California, United States Uploaded by Evan Rude
X / Black Flag Dec 9, 1979 Costa Mesa, California, United States Uploaded by Evan Rude